Optical recording medium recording longest mark at speed which half of lowest guaranteed speed for the recording medium

ABSTRACT

A recordable optical information recording medium having an address t for each sector, comprises: an area A 1  starting from an address t 1  to which access is made only when a recording apparatus performs recording operation; an area A 2  starting from an address t 2  to which access is made either when the recording apparatus performs the recording operation or when the recording apparatus performs reproducing operation; and an area A 3  starting from an address t 3  to which access is made either when either the recording apparatus or a reproducing apparatus performs recording or when either the recording apparatus or the reproducing apparatus performs reproducing. The addresses t are set consecutively with respect to a physical arrangement of the sectors in each of the areas A 2  and A 3 , and the area A 1  has at least one inconsecutive part at which the addresses t are not consecutive with respect to the physical arrangement of the sectors.

This application is a continuation of application Ser. No. 09/793,131filed on Feb. 27, 2001, which claims priority under 35 U.S.C. 119 to thefollowing foreign application: Japanese Application No. 2000-058081,dated Mar. 3, 2000, which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an optical informationrecording medium and a recording apparatus, and, in particular, to anoptical information recording medium and a recording apparatus forhigh-speed recording.

2. Description of the Related Art

Recently, high-speed recording has been rendered for an opticalinformation recording medium such as a write-once compact disk (CD-R), arewriteable compact disk (CR-RW) or the like, to which a light beam isapplied so that a material of a recording layer thereof is changed, and,thereby, information is recorded thereto. Further, there are opticalinformation recording media produced for recording at multiple speeds towhich recording can be made at an arbitrary speed, and, for which it hasbeen requested that a quality in recorded signal obtained from beingrecorded at a high speed is maintained, and, also, it has been requestedthat a quality in recorded signal obtained from being recorded at a lowspeed is satisfactory. Especially, according to the Part III of theOrange Book which is a specification of standards for rewriteablecompact disks, high-speed recording at a speed four times through tentimes, has been being standardized, in contrast to the related art inwhich recording is made at a speed once through four times. Further, forhigh-speed recording, it is difficult to apply a constant linearvelocity (CLV) form to recording apparatuses in consideration of theapparatus performances. Accordingly, it is necessary to apply a constantangular velocity (CAV) form thereto. In order to apply the CAV recordingform, a velocity margin approximately three times is needed for ageneral optical disk having a diameter of 120 mm.

However, a margin in recording speed has reached a limit for opticalinformation recording media. In particular, for phase-change-typeoptical information recording media, it has been difficult to widen themargin in recording speed in consideration of property of recordingmaterial. Accordingly, optical information recording media which can beused only for high-speed recording result basically. However, actually,when a conventional recording apparatus produced for recording at a lowspeed is used, and, a recording medium only for high-speed recording isinserted thereto by mistake, a writing process may be forcibly performedon the recording medium after processes such as setting of a recordingpower through trial writing and so forth. In such a case, due to adifference in material of optical information recording media betweenconventional ones for low-speed recording and new recent ones forhigh-speed recording, it is not possible to perform recording throughthe recording apparatus produced for recording at a low speed,satisfactorily. Accordingly, original data may be erroneously erased, ornonsense writing may be made.

Accordingly, it is necessary that, even from such an optical informationrecording medium only for high-speed recording, reproducing of recordeddata can be performed through a conventional recording apparatus orreproducing apparatus produced for recording/reproducing at a low speedin order that such a recording medium can be used generally and has acompatibility, but, to such a recording medium, recording cannot beperformed through such a recording apparatus produced for recording at alow speed.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an optical informationrecording medium produced for high-speed recording, from whichreproducing recorded data can be performed through a conventionalrecording apparatus or reproducing apparatus produced forrecording/reproducing at a low speed, but, to which recording cannot beperformed by such a recording apparatus produced for recording at a lowspeed.

An recordable optical information recording medium, according to thepresent invention, having addresses t for respective sectors, comprises:

an area A1 starting from an address t1 to which access is made by arecording apparatus only at a time of recording operation;

an area A2 starting from an address t2 to which access is made by therecording apparatus either at a time of recording operation or at a timeof reproducing operation; and

an area A3 starting from an address t3 to which access is made either bythe recording apparatus or a reproducing apparatus either at a time ofrecording or at a time of reproducing, and

wherein the addresses t are set consecutively with respect to a physicalarrangement of the sectors in each of the areas A2 and A3, and the areaA1 has at least one inconsecutive part at which the addresses t are notconsecutive with respect to the physical arrangement of the sectors.

In this configuration, because the addresses t are set consecutivelywith respect to the physical arrangement of the sectors for the areas A2and A3 as in a normal manner, information can be reproduced even fromthe optical information recording medium produced for recording at ahigh speed through a conventional recording apparatus produced forrecording at a low speed or by a reproducing apparatus. On the otherhand, because the area A1 has at least one inconsecutive part at whichthe addresses t are not consecutive with respect to the physicalarrangement of the sectors, an error occurs when the area A1 is accessedat the time of recording operation. Accordingly, it is possible toprovide the optical information recording medium produced for recordingat a high speed to which recording cannot be performed through arecording apparatus produced for recording at a low speed.

The inconsecutive part may have no sector range between an address t1′and an address t2′ which are not consecutive, where t1<t1′, t2′<t2, andthe starting address t1 of the area A1 may be set precedingly by theamount of (t2′−t1′).

Accordingly, although the inconsecutive part is provided, no range inwhich the addresses are not understandable/recognizable exists, andalso, it is possible to secure the area A1 equivalent to that in thecase where this inconsecutive part is not provided.

The inconsecutive part may have a range of A1′ in the direction of thephysical arrangement of the sectors between addresses t1′ and t2′, theaddresses from the address t1′ to the address t2′ are not consecutive,where t1<t1′, and t2′<t2, and arbitrary addresses tx may be set in therange A1′.

Thereby, although the inconsecutive part is provided, it is possible toset arbitrary addresses tx in the range of the inconsecutive part.Accordingly, it is possible to utilize the inconsecutive part by settingadditional information therein.

The inconsecutive part may have a range of Al′ in the direction of thephysical arrangement of the sectors between addresses t1′ and t2′, theaddresses from the address t1′ to the address t2′ are not consecutive,where t1<t1′, and t2′<t2, and there may be no addresses set in the rangeA1′.

Thereby, because no addresses exist in the inconsecutive part, it ispossible to make an error positively occur at the inconsecutive partwhen an attempt is made to record information to the recording mediumthrough a conventional recording apparatus produced for recording at alow speed, and, thus, to prevent writing thereto through this recordingapparatus.

The recording medium may further comprise a pre-pit in the inconsecutivepart.

Thereby, because the pre-pit is provided in the inconsecutive part, itis possible to add information in the inconsecutive part.

The addresses may be recorded in wobbles of a guide groove.

Because the addresses are thus recorded in a form of wobbles of theguide grove of the recording medium, and a track signal is used, it ispossible to specify the addresses separately from a recording signal.

The recording medium may be configured to have a characteristic suchthat, a degree of modulation is equal to or lower than 0.5 obtained whenrecording is made through the recording apparatus employing either anoptical pickup for CD having a wavelength λ=789 nm, and a numericalaperture of an objective lens NA=0.50 or an optical pickup for DVDhaving a wavelength λ=650 nm, and a numerical aperture of an objectivelens NA=0.60, at a relative speed V such that V=0.5 Vmin where Vminrepresents the lowest recordable relative speed between the opticalpickup and the recording medium, with a recording signal of the largestmark length using a light-emitting waveform comprising a multi-pulsesequence.

Accordingly, whether it is for CD or for DVD, the characteristic suchthat the degree of modulation is equal to or smaller than 0.5 isobtained when recording is made at the speed V=0.5 Vmin which is ½ ofthe lowest recording speed Vmin guaranteed for the recording medium.Therefore, recording to the recording medium cannot be performedproperly through a conventional recording apparatus produced forrecording at a low speed, consequently, and, as a result, an erroroccurs such that an OPC error is forwarded in recording of trial writingor the like. On the other hand, the recording characteristic can beimproved for V≧Vmin for the recording medium.

A recording apparatus, according to the present invention comprises:

a detecting part which detects as to whether or not the inconsecutivepart exists in the area A1 of the above-mentioned recording mediumaccording to the present invention; and

a correcting part which performs correlation for the inconsecutiveaddresses thereof when the inconsecutive part is detected by thedetecting part.

In this configuration, when recording to the optical informationrecording medium having the inconsecutive part in the area A1 producedfor recording at a high speed is performed, the detecting part detectsthe inconsecutive part, and the correcting part performs addresscorrection for the inconsecutivity of the addressees thereof. Thereby,it is possible for the recording apparatus to access the area A1 withoutgenerating any problem, and to perform normal recording processing.

Other objects and further features of the present invention will becomemore apparent from the following detailed description when read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 typically illustrates a sector and address structure of anoptical information recording medium in an embodiment of the presentinvention;

FIGS. 2A, 2B and 2C illustrate three examples of relationship betweenthe number of sectors and address in the optical information recordingmedium in the embodiment of the present invention;

FIG. 3 illustrates a waveform of a recording signal used in experimentsperformed for the optical information recording medium in the embodimentof the present invention;

FIG. 4 is a block diagram showing a general configuration of a recordingapparatus in one embodiment of the present invention;

FIG. 5 shows a side elevational sectional view of an example of theoptical information recording medium in the embodiment of the presentinvention; and

FIG. 6 shows an exmaple of relationship between the number of sectorsand address in an optical information recording medium in the relatedgeneral art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

One embodiment of the present invention will now be described based onFIGS. 1 through 5. First, a sector and address structure of an opticalinformation recording medium 1 in the embodiment of the presentinvention to which data recording at a high speed can be performed willnow be described with reference to FIGS. 1 and 2.

Sectors are previously formed in a recording area of the opticalinformation recording medium 1 in the embodiment of the presentinvention at least before information is recorded thereto, and anaddress is assigned to each sector. The addresses are ones which canspecify the corresponding sectors, respectively. Information concerningthese addresses are preferably recorded in a manner in which theinformation is modulated into wobbles of a guide groove of the opticalinformation recording medium 1. For exmaple, ATIP (Absolute Time InPregroove) in CD-R disks or CD-RW disks, and ADIP (Address In Pregroove)in rewriteable DVD+RW disks are examples therefor.

The optical information recording medium 1 has at least three recordableareas A1, A2 and A3 as shown in FIG. 1. The area A1 is an area to whicha recording apparatus accesses only at a time of recording operation (ata time of processing operation in prior to actual recording). Aninformation management area for a recording apparatus or the like is oneexmaple thereof. As an actual example, an area for trial writing beforerecording for setting a recording power for a laser light of an opticalpickup for recording (PCA (Power Calibration Area) in a CD-R disk, CD-RWdisk, DVD+RW disk, or the like) corresponds to the area A1. This area A1extends from a starting address t1 to an end address t2.

The subsequent area A2 is an area to which a recording apparatusaccesses at a time of recording operation and also accesses at a time ofreproducing operation (at a time of processing operation in prior toactual reproducing). For example, this area is used as an area formanaging recorded information in many cases. As an actual example, a PMA(Program Memory Area) in a CD-R disk and a CD-RW disk corresponds tothis area A2. This area A2 extends from a starting address t2 to an endaddress t3.

The subsequent area A3 is an area to which a recording apparatusaccesses at a time of recording (at a time of execution of actualrecording processing) and at a time of reproducing (at a time ofexecution of actual reproducing processing), and an apparatus (only) forreproducing accesses at a time of reproducing. To this area, information(data) is actually recorded. A program area in a CD-R disk and a CD-RWdisk corresponds to this area A3. This area A3 starts from a startingaddress t3.

For a conventional optical information recording medium produced forrecording at a low speed, as shown in FIG. 6, addresses t areconsecutively assigned and set according to a predetermined rule,according to a physical arrangement of sectors on the opticalinformation recording medium. That is, a relationship between thephysical arrangement of the sectors and addresses is, as shown in FIG.6, such that, as the number of sectors increases (or decreases), theaddress increases, and, according to a rule particular to the recordingmedium, the address always changes consecutively. A recording apparatusdetects an absolute position on the optical information recording mediumfrom the address, and performs recording thereto. However, for anoptical information recording medium produced for recording at a highspeed, if the sector and address structure shown in FIG. 6 is appliedthereto, there is a possibility that even an apparatus produced only forrecording at low speed can also perform recording thereto forcibly.

In this point, the optical information recording medium 1 in theembodiment of the present invention has the area A1 which is accessedonly at a time of recording operation and is previously formatted sothat at least one inconsecutive part at which the addresses t are notconsecutive with respect to the physical arrangement of sectors isprovided. This inconsecutive part is set between an address t1′ throughan address t2′. These addresses t1′ and t2′ are those such thatt1<t1′<t2′<t2 in the area A1.

The assesses t1′ and t2′ of the inconsecutive part are determined basedon a point at which a recording apparatus produced for recording at alow speed, for which recording thereto is to be prevented, accesses inthe area A1. For exmaple, when the recording apparatus produced forrecording at a low speed accesses an address t0 in the area A1 at a timeof recording operation, the addresses t1′ and t2′ are set so that theabove-mentioned address t0 is in the inconsecutive part, that is, thisaddress t0 is included between the address t1′ through t2′.

A form of this address-t inconsecutive part may be set arbitrarily.FIGS. 2A, 2B and 2C show three typical examples in pattern of the formof the address-t inconsecutive part. FIG. 2A shows a pattern in whichthe inconsecutive part 2 has no sector range. In this exmaple, nosectors exist between the addresses t1′ and t2′, as shown in FIG. 2A,and thereby the addresses are not consecutive at this inconsecutive part2. In this case, in comparison to the address setting in the generalrelated art shown in FIG. 6, the number of sectors included in the areaA1 is smaller by the number corresponding to the addresses t1′ throught2′ of the inconsecutive part 2. Therefore, the starting address t1 ofthe area A1 is set precedingly for this difference (reduction).Specifically, t1−(t2′−t1′) is set as the starting address of the area A1in this case. According to this arrangement, it is possible to form theinconsecutive part 2 at which the addresses t are not consecutivewithout decreasing the number of useable sectors included in the areaA1, and, also without providing any area in which the address t are notunderstandable/recognizable.

FIG. 2B shows an exmaple in which the inconsecutive part 3 at which theaddresses t are not consecutive is formed having a range A1′ in thedirection of the physical arrangement of sectors. In this case,arbitrary addresses tx can be freely set in the range A1′ of theinconsecutive part 3. Accordingly, by setting arbitrary addresses tx inthe inconsecutive part 3, it is possible to cause the range A1′ to haveadditional information using the addresses tx such as description of thetype of recording medium, or the like in the inconsecutive part 3 atwhich the addresses t are not consecutive.

FIG. 2C shows an example in which the inconsecutive part 4 is formedsimilar to the above-mentioned inconsecutive part 3 shown in FIG. 2B.However, the range A1′ of the inconsecutive part 4 has no addresses t.For example, in order to cause the inconsecutive part 4 to have noaddresses, in a case where the addresses are recorded through wobblemodulation of a pregroove (guide groove), wobble modulation is not made,the wobbles themselves are not provided, or the pregroove itself is notprovided therein. When the pregroove itself is not provided therein, apre-pit may be set in the area A1 so as to prevent track removal whenthe range A1′ of the inconsecutive part 4 is long. In this case, it ispossible to arbitrarily set information to be recorded in the pre-pit.By providing the inconsecutive part 4 having no addresses, it ispossible that an error is positively caused to occur when an attempt ofrecording to the optical information recording medium 1 is made througha recording apparatus produced for recording at a low speed, asdescribed later.

A medium property of the optical information recording medium 1 in theembodiment of the present invention is improved so that recordingthereto at a high speed can be rendered. However, it is preferable thatthe following setting is made such that recording through a recordingapparatus produced for recording at a low speed can be positivelyprevented. That is, when an optical pickup for CD of wavelength λ=789 nmand numerical aperture of objective lens NA=0.50 or an optical pickupfor DVD of wavelength λ=650 nm and numerical aperture of objective lensNA=0.60 is used, it is preferable that characteristics obtained whenrecording is performed at a relative speed which is ½ of the lowestspeed Vmin guaranteed for the recording medium (lowest recordablerelative speed) between the pickup and recording medium, that is,V=0.5Vmin, are as follows. In this case, as a recording signal, as shownin FIG. 3, a multi-pulse sequence including repetitions of heatingpulses and cooling pulses, and, having the maximum mark length of 11T.The recording power Pw is set arbitrarily, and, the erasing power Pe isset as 0.5 Pw. In this condition, the degree of modulation m₁₁(=I₁₁/Rtop, where Rtop represents the maximum reflectance for a portionat which information is not written, and I₁₁ represents the reflectancefor a portion at which the maximum mark length 11T is recorded) ismeasured when the signal recorded to the optical information recordingmedium 1 is reproduced by using the optical pickup used in therecording, and the degree of modulation m₁₁ is such that m₁₁≦0.5. In theoptical information recording medium 1 having the above-mentionedcharacteristics, it is possible to increase the degree of modulation atthe maximum recording speed Vmax guaranteed for the recording medium,and to obtain stable characteristics of recorded signal when recordingis performed at a high speed.

A recording apparatus 5 in an embodiment of the present invention whichcan perform recording information to the optical information recordingmedium 1 to which recording can be performed at a high speed will now bedescribed with reference to FIG. 4. Basically, a configuration forpreventing the above-mentioned inconsecutive part 2, 3 or 4 from havingany influence at a time of recording operation is provided. In thisrecording apparatus 5, although details are omitted, an optical pickup 7including a laser light source, an objective lens, a photodetector andso forth for applying a light beam for recording or reproducing to theoptical information recording medium 1 which is driven and rotated by aspindle motor 6, a read-signal processing part 8 which performsextraction of an address signal from a read signal detected by thephotodetector of the optical pickup 7, an address-signal processing part9 which performs demodulation processing on the address signal obtainedfrom the read-signal processing part 8, an address-inconsecutivitydetecting part 10 which detects whether or not address inconsecutivityexists, based on the output of the address-signal processing part 9, anaddress correcting part 11 which performs predetermined addresscorrection when address inconsecutivity is detected by theaddress-inconsecutivity detecting part 10, and a recording-apparatuscontrol part 12 provided for controlling the laser light source in theoptical pickup 7.

In the above-mentioned configuration of the recording apparatus 5, thelight beam is condensed and applied to the optical information recordingmedium 1 which is driven and rotated by the optical pickup 7, thereflected light from the optical information recording medium 1 isreceived by the photodetector, and, thereby, a signal is read out fromthe optical information recording medium 1. Only an address signal isextracted from the thus-read signal by the read-signal processing part8. The thus-extracted address signal is demodulated by theaddress-signal processing part 9, and, thereby, a point at which thelight beam is currently applied to the optical information recordingmedium 1 is specified. At this time, in a recording apparatus producedfor recording at a low speed in the general related art which does nothave the address-inconsecutivity detecting part 10, when addressinconsecutivity occurs as a result of the inconsecutive part 2, 3, or 4being accessed, it is determined that tracking failure has occurred, andan error signal is forwarded to the recording-apparatus control part 12.Accordingly, it is not possible that subsequent processing, that is,trial writing and recording processing which is to be performed in anormal state, cannot be performed. Thereby, writing of information tothe optical information recording medium 1 is prevented from beingperformed by the recording apparatus produced for recording at a lowspeed.

In contrast to this, in the recording apparatus 5 in the embodiment ofthe present invention described with reference FIG. 4, theaddress-inconsecutivity detecting part 10 and address correcting part 11are provided, and address information concerning the inconsecutive part2, 3 or 4 in the area A1 of the optical information recording medium 1is previously recognized. Accordingly, when address inconsecutivityoccurs at an access to the area A1, the address-inconsecutivitydetecting part 10 recognizes that the address inconsecutivity hasoccurred due to the inconsecutive part 2, 3 or 4, and outputs thismatter to the address correcting part 11. As a result, the addresscorrecting part 11 performs address correction such that the addressesat the inconsecutive part 2, 3 or 4 are skipped, and then, outputsaddress information to the recording-apparatus control part 12. Thus,without being affected by the address inconsecutivity due to theinconsecutive part 2, 3 or 4, and, through predetermined control by therecording-apparatus control part 12 or the like, trial-writingprocessing by accessing the area A1 (setting of the recording power Pw)and so forth is performed. Thereby, it is possible to perform recordingprocessing to the area A3 or the like, which is to be performed in thenormal state.

With regard to reproducing processing performed through a recording orreproducing apparatus, whether it is produced for recording at a lowspeed or a high speed, no access to the area A1 is performed, and,access to the areas A2 and A3 in which the addresses t are setconsecutively according to the physical arrangement of sectors isperformed. Therefore, reproducing processing can be rendered withoutoccurrence of any problems.

At least the above-described processing performed by theaddress-inconsecutivity detecting part 10 and address correcting part 11may be performed by a general-purpose computer as a result ofinstructions written in a software program including program code meansfor performing the processing to be executed thereby. The softwareprogram may be recorded in a carriable recording medium such as aCD-ROM, which is read therefrom through a CD-ROM drive, and is providedto the CPU of the computer. Then, the CPU performs the processingaccording to the program.

Actual examples of the above-described of the optical informationrecording medium 1 in the embodiment of the present invention describedabove will now be described.

FIRST EXAMPLE

A substrate for a CD-RW was prepared in which, on a transparentsubstrate made of polycarbonate, a continuous guide groove was formedspirally. For address information (ATIP) to be recorded in the guidegroove, the inconsecutive part 2 of ATIP inconsecutivity in a form asshown in FIG. 2A was formed at the address t1′ and t2′ in the followingmanner:

-   -   t1=96:25:10    -   t1′=96:41:49    -   t2′=97:11:50    -   t2=97:23:50    -   t3=97:27:00

An area in which the above-mentioned inconsecutive part 2 was formed isa PCA, which is an area to which trial writing is performed with thepower being changed, in order to determine the recording power Pw, at atime of recording operation, by a recording apparatus. The addresses t1′and t2′ were determined in consideration of a position at which therecording apparatus accesses at a time of the recording operation.

Further, for the area other than the inconsecutive part 2, ATIPinformation which can be used for 1 through 4 times (1× through 4×) of anormal reproduction speed of a compact disk which is produced inaccordance with the Orange Book, Part III, ver. 2.0, which is thespecification of standards for CD-RW was recorded thereto.

Then, as shown in FIG. 5, onto the thus-obtained transparent substrate13, a lower dielectric layer 14, a recording layer 15, an upperdielectric layer 16, a metal reflection layer 17 and a protection layer18 were formed. Thus, the optical information recording medium 1 wasobtained. Each of the lower and upper dielectric layers 14 and 16 weremade of a mixture mainly containing ZnS and SiO₂, the recording layer 15was made of a phase-change material mainly containing AgInTeSb, and themetal reflection layer 17 was made of a material mainly containing A1.Further, the lower and upper dielectric layers 14 and 16 were formed byRF spattering, and the recording layer 15 and metal reflection layer 17were formed by DC spattering. The protection layer 18 was formed as aresult of a film of a UV curing resin being deposited by spin coating,and then, UV light being applied thereto so as to cure it.

By initializing the thus-obtained optical information recording medium 1through a CD-RW initializing apparatus, it was possible to obtain anot-yet-recorded CD-RW recording medium. Thus-obtained recording mediumhas the above-mentioned inconsecutive part 2 at which addresses are notconsecutive formed in the PCA area.

An experiment was performed so as to determine whether or not recordingcan be made to this CD-RW recording medium having the inconsecutive part2 at which addresses are not consecutive in the PCA area as mentionedabove, through a recording apparatus (produced for recording at a lowspeed) available at stores. The recording apparatus used is a CD-R/RWdrive MP-7060A made by Ricoh Company Ltd. When an attempt was made torecord information to the CD-RW recording medium through this recordingapparatus, an error occurred at an initial stage of recording operation,and the recording medium was ejected by the apparatus.

On the other hand, the above-mentioned recording apparatus was modifiedso as to additionally include the above-mentionedaddress-inconsecutivity detecting part 10 and address correcting part11, and, then, the attempt was made to record information to the CD-RWrecording medium (optical information recording medium 1) through thismodified recording apparatus. As a result, although inconsecutivity ofATIP exists in the PCA area due to the inconsecutive part 2, the addresscorrecting part 11 performed correction for the addresses for 00:30:00in the inconsecutive part 2 which are not consecutive. Thereby,recording operation such as trial writing and so forth was performedwithout occurring any problem, and, then, actual recording was startedby the recording apparatus. Thus, it was confirmed that, while recordingcan be performed to the optical information recording medium 1 in theembodiment of the present invention through the recording apparatus 5 inthe embodiment of the present invention, recording cannot be performedto the same optical information recording medium 1 through the original(not modified) recording apparatus produced for recording at a lowspeed.

SECOND EXAMPLE

A CD-RW recording medium was produced in a manner similar to that in thecase of the above-described first example. However, the compositionratio of the material of the recording layer thereof was changed so thatrecording at a high speed such as 4× through 8× can be performedthereon. Then, a CD-RW disk evaluating apparatus DDU1000 (λ=789 nm,NA=0.50) was used, and recording was performed on the thus-producedCD-RW recording medium at speeds of 8×(V=9.6 m/s), 4×(V=4.8 m/s) and2×(V=2.4 m/s) with the recording signal of multi-pulse waveform shown inFIG. 3. The recording power Pw was determined by an OPC method which isin accordance with the Orange Book, Part III, ver. 2.0, which is thespecification of standards for CD-RW.

The thus-recorded signals were read at a reproduction speed of 1×, andthe above-mentioned degree of modulation m₁₁ for each recording speedwas measured. As a result, the following results were obtained:

-   -   8×: I₁₁/Rtop=0.65    -   4×: I₁₁/Rtop=0.56    -   2×: I₁₁/Rtop=0.45

Thus, the sufficient degrees of modulation were obtained for therecording signals for the recording speeds of 8× and 4×. However, thedegree of modulation was low for a low speed such as 2× in aconventional manner, and is lower than 0.55 which is the lowest standardvalue for CD-RW. Accordingly, the optical information recording medium 1in the embodiment of the present invention is a recording medium towhich recording cannot be performed properly at a low speed such as 2×.

Then, when an attempt was made to write information to theabove-mentioned CD-RW recording medium through the above-mentionedconventional recording apparatus which was not modified and thus doesnot have the address-inconsecutivity detecting part 10 and so forth andwas used for the above-mentioned first exmaple, the CD-RW recordingmedium was ejected by the recording apparatus before recording is made,similarly.

The present invention is not limited to the above-described embodiments,and variations and modifications may be made without departing from thescope of the present invention.

The present application is based on Japanese priority application No.2000-058081, filed on Mar. 3, 2000, the entire contents of which arehereby incorporated by reference.

1. An optical information recording medium having addresses t forrespective sectors, on which information is recorded through applicationof light thereto, said recording medium being arranged such that adegree of modulation obtained, when recording of the longest record markis made thereon at a recording speed of V=0.5Vmin, wherein Vmin is thelowest recording speed guaranteed for the optical information recordingmedium, is lower than the lowest standard value of the opticalinformation recording medium.
 2. The optical information recordingmedium as claimed in claim 1, wherein: the minimum recording speed Vminguaranteed for the optical information recording medium is 4 times anormal reproduction speed of a compact disk.
 3. The optical informationrecording medium as claimed in claim 1, wherein: the lowest standardvalue of the optical information recording medium is 0.55.
 4. Theoptical information recording medium as claimed in claim 1, having aconfiguration in which, on a transparent substrate, a lower dielectriclayer, a recording layer, an upper dielectric layer, a metal reflectionlayer and a protection layer.
 5. The optical information recordingmedium as claimed in claim 4, wherein: said recording layer mainlycomprises AgInTeSb.
 6. The optical information recording medium asclaimed in claim 4, wherein: said lower dielectric layer and upperdielectric layer mainly comprise ZnS and SiO₂.
 7. The opticalinformation recording medium as claimed in claim 4, wherein: said metalreflection layer mainly comprises A1.
 8. The optical informationrecording medium as claimed in claim 1 comprises a phase-changerecording medium.
 9. The optical information recording medium as claimedin claim 1, comprises a CD-RW.